P0102
Volume Air Flow Sensor Circuit:
Connectors:
CIRCUIT OPERATION
- The volume air flow sensor power is supplied from the MFI relay (terminal 4), and the ground is provided on the ECM (terminal 40)
- 5-volt power is applied to the volume air flow sensor output terminal (terminal 3) from the ECM (terminal 90)
TECHNICAL DESCRIPTION
- while the engine is running, the volume air flow sensor outputs a pulse signal which corresponds to the volume of air flow.
- The ECM
DTC SET CONDITIONS
Check Conditions
- Engine speed is higher than 500 r/min.
Judgement Criteria
- Volume air flow sensor output frequency has continued to be 3.3 Hz or lower for 2 seconds.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Volume air flow sensor failed.
- Open or shorted volume air flow sensor circuit, or loose connector.
- ECM failed.
- PCM failed.
- Air leak between volume air flow sensor and throttle body.
DIAGNOSIS
Required Special Tools
- MB991502: Scan Tool (MUT-II)
STEP 1. Using scan tool MB991502, check data list item 12: Volume Air Flow Sensor.
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Start the engine and run at idle.
3. Set scan tool MB991502 to the data reading mode for item 12, Volume Air Flow Sensor
4. Warm up the engine to normal operating temperature: 80 °C to 96 °C (176 °F to 205 °F).
- The standard value during idling should be 10 Hz or more.
- When the engine is revved, the frequency should increase according to the increase in engine speed.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points.
NO: Go to Step 2.
STEP 2. Check the power supply voltage at volume air flow sensor connector B-105 by backprobing.
1. Do not disconnect the connector B-105.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 4 and ground by backprobing.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 5.
NO: Go to Step 3.
STEP 3. Check the power supply voltage at volume air flow sensor harness side connector B-105.
1. Disconnect the connector B-105 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 4 and ground.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 4.
NO: Repair harness wire between MFI relay connector B-12X terminal 4 and volume air flow sensor connector B-105 terminal 4 because of open circuit or short circuit to ground. Then go to Step 13.
STEP 4. Check connector B-105 at the volume air flow sensor for damage.
Q: Is the connector in good condition?
YES: Repair harness wire between MFI relay connector B-12X terminal 4 and volume air flow sensor connector B-105 terminal 4 because of harness damage. Then go to Step 13.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 13.
STEP 5. Check connector B-105 at volume air flow sensor for damage.
Q: Is the connector in good condition?
YES: Go to Step 6.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 13.
STEP 6. Check the sensor supply voltage at volume air flow sensor harness side connector B-105.
1. Disconnect the connector B-105 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 3 and ground.
- Voltage should be between 4.8 and 5.2 volts.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 9.
NO: Go to Step 7.
STEP 7. Check connector C-115 at ECM
Q: Is the harness connector in good condition?
YES: Go to Step 8.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 13.
STEP 8. Check for short circuit to ground between volume air flow sensor connector B-105 terminal 3 and ECM connector C-115 terminal 90
Q: Is the harness wire in good condition?
YES: Replace the ECM or PCM. Then go to Step 13.
NO: Repair it. Then go to Step 13.
STEP 9. Check the continuity at volume air flow sensor harness side connector B-105.
1. Disconnect the connector B-105 and measure at the harness side.
2. Check for the continuity between terminal 5 and ground. Should be less than 2 ohm.
Q: Is the continuity normal?
YES: Go to Step 12.
NO: Go to Step 10.
STEP 10. Check connector C-119 at ECM
Q: Is the connector in good condition?
YES: Go to Step 11.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 13.
STEP 11. Check for open circuit and harness damage between volume air flow sensor connector B-105 terminal 5 and ECM connector C-119 terminal 40
Q: Is the harness wire in good condition?
YES: Replace the ECM or PCM. Then go to Step 13.
NO: Repair it. Then go to Step 13.
STEP 12. Check connector C-119 at ECM
Q:
YES: Replace the volume air flow sensor. Then go to Step 13.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 13
STEP 13. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to, Procedure 6 - Other Monitor.
2. Check the diagnostic trouble code (DTC).
Q: Is the DTC P0102 output?
YES: Retry the troubleshooting.
NO: The inspection is complete.